|Message NO SENSOR||
The current in the cable to this sensor is below 20 mA. Normally this means that there is no sensor connected to the cable or that there is no cable to the DTR. If this message comes up while a sensor properly is connected, the most likely cause of this message is a fault in the sensor. It is also possible that the cable is totally dead for example if it is accidentally cut through.
See also Diagnostic LED LD1/LD3, Diagnostic LEDs. The concentration display is a dashed line.
Message NO SIGNAL
Besides the message, the concentration display is a dashed line although a sensor is connected.
The current in the cable to this sensor is in the correct range 20 … 60 mA, but no data is coming in from the sensor. This indicates that the Sensor processor card is faulty.
See also Diagnostic LED LD1/LD3, Diagnostic LEDs.
|Replace the sensor processor card.|
The current in the cable to the sensor A/B exceeds 60 mA. First, the DTR attempts for a short time to reconnect with the sensor in question. If the short-circuit persists, the sensor in question is switched off completely to protect the Motherboard from overheating.
See also Diagnostic LED LD2/LD4, Diagnostic LEDs
If the DTR detects a short-circuit that persists, the affected sensor is switched off to prevent further damage. The message SHORT-CIRCUIT stays on the screen until the DTR is powered off and on.
See also Diagnostic LED LD2/LD4, Diagnostic LEDs
The most likely cause of these messages is a problem in the cable connecting the sensor in question to the DTR. Check that the cable is undamaged and replace it if necessary, then turn the DTR off and back on.
|Message HIGH SENSOR HUMIDITY||
Tells that humidity measured at the Sensor processor card exceeds 60 % relative humidity. The reason may be moisture leaking in through prism seal or the cover being open. Also, check and, if necessary, replace prism seal.
|Message HIGH SENSOR TEMP||
The temperature on the sensor processor card exceeds +65 °C (+150 °F). To read this temperature, go to.
|For action, see Choosing sensor mounting location.|
|Message HIGH TRANSMITTER TEMP||
The temperature of the motherboard of the indicating transmitter exceeds +60 °C (+140 °F). To read this temperature, go toand check DTR TMP. If the warning persists, move the transmitter to a cooler place (for example out of the sun).
|Message LOW TRANSMITTER VOLT||The internal DC voltages of the transmitter are below specifications.||Check the power supply input voltage. If the supply voltage is within specifications, replace power supply module, Figure 1.|
|Relays and switches not working||
Relay status is indicated by LEDs D23, D25 on the Motherboard, see Diagnostic LEDs. For switches, check also LED D26 on the Motherboard indicating that the 3 V DC supply is correct, see Diagnostic LEDs.
The wash function can be tested according to Testing prism wash.
|Output signal error during NORMAL OPERATION||
If there is no output signal:
If the mA signal does not correspond to the concentration display, check output signal configuration, see Viewing system information, and for possible correction see Configuring mA outputs. A low mA signal can also be caused by high resistance in the external current loop, see Connecting the sensor to the indicating transmitter.
A noisy signal can be damped, see Configuring output signal damping.
|Message OUTSIDE LIGHT ERROR||The measurement is not possible because too much outside light reaches the camera.||Identify the light source (for example sun shining into an open tank or a translucent pipe) and block the light from getting to the prism at the sensor tip.|
|Message NO OPTICAL IMAGE||
|Message PRISM COATED||The optical surface of the prism is coated by the process medium or impurities in the process medium.||
Perform prism wash if available, see Testing prism wash. Remove sensor from line and clean prism manually.
|Message OUTSIDE LIGHT TO PRISM||Some light from the outside reaches the sensor and may disturb the measurement.||Identify the light source (for example sun shining into an open tank or a translucent pipe) and block the light from getting to the prism at the sensor tip.|
|Message LOW IMAGE QUALITY||The most likely cause for this message is scaling on the prism. There still is a optical image available, but the measurement quality may not be optimal.||Clean the prism.|
|Message NO SAMPLE||The operation of the equipment is OK but there is no process liquid on the prism. The optical image looks like the left image in Figure 1.|
|Message TEMP MEASUREMENT FAULT||Indicates faulty temperature element.||
Replace the temperature element.
|Concentration drift during NORMAL OPERATION||For drift upward, suspect prism coating, see Prism coating. Otherwise check calibration, see Calibrating concentration measurement, and sensor verification, see Sensor verification.|
|Message EXTERNAL HOLD||The concentration measurement is on HOLD due to an external switch closure. For explanation, see Configuring input switches.|
|Messages PRECONDITIONING, WASH, RECOVERING||PRECONDITIONING: An optional preconditioning relay is closed.||See Configuring prism wash.|
|WASH: The internal wash relay is closed.||Configuring prism wash.|
|RECOVERING: The concentration measurement is on HOLD during a preset time.|
|Message PRISM WASH WARNING|
|Message PRISM WASH FAILURE|
|Message EXTERNAL WASH STOP||
Tells that wash action is prevented because an EXTERNAL WASH STOP switch is closed, see Configuring input switches.
|Message LOW TEMP WASH STOP||
Tells that wash action is prevented because of LOW TEMP: low process temperature indicates empty pipe.
|To set the limit, see Configuring prism wash.|
|Message NO SAMPLE / WASH STOP||Tells that wash action is prevented because of NO SAMPLE: the process pipe is empty and the prism is clean.|